It is difficult to set out guidelines for font usage, because almost
any rule can be brilliantly broken under the right circumstances.

General guidelines:

Never lose track of the kind of work you're doing. An effect that
would ruin a newsletter might be just the thing for a record cover.
Know when you can safely sacrifice legibility for artistic effect.

Keep in mind the final reproduction process you'll be using. Some
effects (like reversed type, white on black) can be hard to read off
an ordinary 300-dpi laser, but will work if finals are done on a
high-resolution printer, such as a Linotronic. Will the pages be
photocopied? Offset? Onto rough paper, shiny paper? All these factors
can and should influence your choice of fonts and how you use them.

Running some comparative tests is a good idea. Better to blow off a
few sheets of laser paper now than to see a problem after thousands of
copies are made.

No one can teach you font aesthetics; it must be learned by example.
Look at beautiful magazines, posters, books with wide eyes, so that
you can see how it's done. Examine ugly printed matter critically and
consider why it's hard to read.

Good rules of thumb:

If you need a condensed font, find one that was designed that way,
rather than scaling an existing font down to a percentage. Any
scaling distorts a font's design; excessive scaling interferes with
legibility - this goes for widening as well as narrowing. Extended
faces do exist, although they aren't as common as condensed ones.

Many people feel that bold or italic type, or type in ALL CAPS, is
more legible: ``This is the most important part of the newsletter,
let's put it in bold.'' In fact, legibility studies show that such type
is actually harder to read in bulk. Keep the text in a normal style
and weight, and find another way to emphasize it - box it, illustrate
it, run it in color, position it focally.

Too much reverse type - white on black - is hard on the eyes. It can
be a nice effect if used sparingly. Don't reverse a serif font, though
- its details will tend to fill in. Stick to reversing bold
sans-serifs, and remember to space them out a bit more than usual.

It is always safest to use a plain serif font for large amounts of
text. Because Times is widely used, it doesn't mean it should be
avoided. Fonts like Palatino, Times, Century Old Style are deservedly
popular because people can read a lot of text set in such faces
without strain.

As point size gets bigger, track tighter, and (if the software allows)
reduce the spacebands as well. A spaceband in a headline size
(anything over 14 point) should be about as wide as a letter ``i''.

If you only have a few large headlines, hand-kerning the type, pair by
pair, can make the end result much more pleasing. Besides, working
with fonts this closely makes them familiar.

Column width and justification are major elements in design. The
narrower the column, the smaller the type can be; wide rows of small
type are very hard to read. Often it's a better idea to set narrow
columns flush left rather than justified, otherwise large gaps can
fall where hyphenation isn't possible.

Use curly quotes.

Don't put two spaces at the end of a line (. ) instead of (. ) when
using a proportionally spaced font.